In recent years, the petroleum industry has invested heavily in the development of improved marine survey techniques and seismic data processing methods in order to increase the resolution and accuracy of seismic images of subterranean formations. Marine surveys illuminate a subterranean formation located beneath a body of water with acoustic energy produced by one or more submerged seismic sources. A source may be composed of an array of source elements, such as air guns or marine vibrators. The acoustic energy may travel down through the water and into the subterranean formation. At each interface between different types of rock or sediment of the subterranean formation a portion of the acoustic energy may be refracted, a portion may be transmitted, and a portion may be reflected back toward the subterranean formation surface and into the body of water. A typical marine survey is carried out with a survey vessel that passes over the illuminated subterranean formation while towing elongated cable-like structures called streamers. Some marine surveys utilize receivers attached to ocean bottom nodes or cables, either in conjunction with, or in lieu of, receivers on towed streamers. The streamers may be equipped with a number of collocated, pressure and particle motion sensors that detect pressure and particle motion wavefields, respectively, associated with the acoustic energy reflected back into the water from the subterranean formation. The pressure sensors generate seismic data that represents the pressure wavefield and the particle motion sensors generate seismic data that represents the particle motion (e.g., particle displacement, particle velocity, or particle acceleration) wavefield.
However, techniques used to determine the structure and composition of a subterranean formation from marine seismic data often depend on assumptions about the marine survey conditions. For example, typical marine data processing techniques assume a flat free surface with a reflection coefficient of −1. However, the flat free surface assumption is not a valid assumption in cases where marine seismic data is collected under rough sea conditions. Those working in marine seismology continue to seek methods and systems to extract information from marine seismic data that more accurately account for changing conditions in a marine survey.